Change
by coffeeandhope
Summary: 4x20 Post-Ep, AU of sorts. Based on the tumblr prompt.
1. Chapter 1

Based on the anonymous tumblr prompt (via castlefanficprompts):

_4x20. Beckett goes out with Colin for that drink. Hours later after Hunt has left, Castle gets a call from his bartender at the Old Haunt, asking if he could come get Detective Beckett because she was too drunk to drive home._

* * *

"Casssle," Beckett drawls, slipping off of her barstool and struggling to stay on her feet.

He immediately slips an arm around her, his anger at her pushed aside by concern for her safety. "What happened, Nick?" Castle asked, looking to the bartender for help.

The kid's fresh out of college and still not used to the drunken patrons that frequent the city's bars, so it takes him a minute to find his voice. "She had a couple of drinks with some blonde guy… British, I think."

Castle grimaces.

_Hunt._

The kid sighs, nervously wiping down the bar for what must have been the hundredth time since he called Castle. "Anyway, the guy had a plane to catch and she told him that she was fine to drive home." Nick eyes Beckett, who's currently leering at Castle as her hands wander. "That was about five shots ago."

"Why'd you let her keep drinking?" Castle asks, the words coming out much harsher than he'd intended.

"She's a hard person to say no to," Nick answers sheepishly.

Castle sighs and looks down at the semi-conscious woman in his arms. Regardless of what state she's in, it's never easy to refuse her. But in this moment she can barely keep her eyes open, let alone walk or drive, so Castle makes an executive decision and grabs her purse and coat. "You good to close up tonight?"

Nick nods and returns to his excessive countertop cleaning.

Castle balances Beckett's belongings in one arm and her body in the other, finally stopping to remove those damn heels as he helps her into his town car.

His driver doesn't question the pair, simply clicks on the _Favorites_ section of his GPS and begins the drive to Beckett's apartment.

Beckett's head lolls to the side and she blinks up at Castle with those big, hazel orbs. When he doesn't say anything, simply looking out the opposite window, she reaches up – rather boldly, thanks in no small part to the alcohol – and turns his cheek so that he's facing her. "Why don't you look at me anymore?"

Her voice is too vulnerable to look away, but Castle can't bring himself to make eye contact either, so he settles on the Omega at her wrist. "I look at you."

She whimpers and maneuvers herself into a semi-straddle in his lap. Castle immediately tenses but can't make himself push her away. Her lithe body is too much to handle and he struggles enough just trying to suppress the shivers at the feeling of her chest flattened against his. "Not like you used to."

"Wha, what?" Castle stumbles over his own words for once in his life.

"You don't look at me like you used to." She dips her head to his chest, the vodka strong on her breath.

"Yeah, well – a lot has changed."

"Like what?" she asks, again whimpering.

"You know what I'm talking about, Beckett."

She sighs, "And it's always Beckett. Never Kate."

Beckett dips her head to his chest at that point, forehead meeting collarbone. The car swerves as she does so and her body goes to follow but Castle wraps his arms around her, keeping her from falling.

She begins to shake and soon enough Castle finds the shoulder she's leaning on is wet, damp with her despair. He does the only thing he can think of and cups her skull, stroking her back with the other hand. "Shh…"

"I'm so sorry, Castle. I'm so sorry." He doesn't say that it's okay – because it's not, and he can't add to the lying in their relationship – and simply holds her tighter. "Castle," she sighs, fingers skimming his ribs and resting so that they're cheek to cheek. "I don't know what I did wrong."

He freezes, realizing for the first time that Beckett might not know what he heard. "You could have just told me, Kate." She molds herself to him. "It would have saved us both a lot of misery."

Her cold nose finds it way to the skin of his neck. "You were supposed to wait for me."

"Wait for what? For you to tell me that you don't lo- that you don't feel the same way?" He barks out the last bit, harsher than he'd meant to for the second time that night. His driver glances back quickly, and Castle avoids meeting his curious gaze.

"Rick, please." Neither are quite sure what she's asking, but Castle continues stroking her hair. "Thank you," she murmurs a few blocks later. Castle can't decide if he's grateful or irritated that her apartment is so far away from the Old Haunt. "Thank you for taking me home." She shifts in his lap again, sniffling. "I know Nick could have just called a cab."

"Oh, Kate." He struggles to blink back any unwanted feelings. "You've ruined me for anyone else." He sighs; keeping his voice low, to the point that she feels more than hears his words. "If you don't know that by now, obviously we're doing something wrong." Castle notes that they've turned onto her street and is suddenly filled with a sense of dread, accompanied by adrenalin. Nostalgia maybe, if that's even possible. "I'm yours, Kate. If nothing else, just know that."

She sniffs against his chest as the car comes to a halt, and Castle holds his breath, equal parts frightened and proud of what he'd just shared. But when she doesn't move, Castle pulls her away from his body to find that she's fallen asleep.

Not knowing how long she'd been awake, or how much she'd remember once she sobered up, Castle lifted her out of the car and carried her to her building.

It wasn't until he'd fished Beckett's keys out of her bag and carried her to her bedroom that she stirred, reaching for him from her bed. "Mhmm, stay with me, Castle." He pauses, considering her request as he places a glass of water and two Ibuprofen at her bedside.

"Can't."

She sighs, rather adorable when she's flustered, but he can't be thinking that way. "Until tomorrow then?" She asks, settling into her bed as her eyes begin to drift closed again.

"'Night, Beckett."

Castle turns away before he can change his mind, heartbroken and still madly in love with her, before locking up and retreating to his town car.

It's not until they're well on their way to Broome Street that he thinks about dedicating the next few weeks solely to his book, avoiding the precinct until he can clear his head and give _Frozen Heat_ the ending it deserves. Maybe he'll give Jameson Rook the ending _he _deserves, an ending.


	2. Chapter 2

Beckett wakes up the next morning with a pounding headache and a hollowed-out heart, but it's not until she's taken the Ibuprofen that she begins to remember. The memories are in pieces and she struggles to recover them, even under the cold spray of her shower, but one thing weighs heavily in her mind. Castle.

_Castle._

Beckett finishes up in the shower and hurries to change into a pair of jeans and a t-shirt, all the while thankful that it's her day off.

She remembers bits and pieces, but one thing is clear; he still loves her. And that means everything right now.

Beckett considers using her police siren on the way to the loft but decides against it and just speeds the rest of the way. She may not remember much from last night, but she needs him to know the truth… Not whatever she did – or didn't – say while drunk.

God, he heard her. He knew that she knew. And she silently curses herself, not blaming him for giving her the cold shoulder the past few weeks.

* * *

It's with this newfound vigor that Beckett squeezes into the only parking spot in front of Castle's building, barely remembering to lock the cruiser as she jogs into the lobby.

Martin the doorman gazes at her wearily – making her wonder in what state Castle arrived home last night – but lets her in regardless. She makes her way to the elevator, thumb probably leaving a permanent impression on the 'up' button, but she couldn't care less.

She's thankful for the lack of neighbors this Sunday, fully aware that any hope of coherent small talk is nonexistent.

The first and only time that she falters is right before knocking. Four years of insecurities bubble up in her chest, but Beckett forces them aside. Four years is long enough.

Beckett's not quite sure what she had been expecting, but Alexis was certainly not it. The girl looks less than happy to see her, eyebrows immediately knitting together and shoulders hunching.

"Detective Beckett."

The older woman sighs and fiddles with the chain around her neck. "Alexis, hi. And it's Kate… You can call me Kate." Alexis doesn't invite her in, but cracks the door open slightly more. "Is your dad home?"

Alexis' piercing blue eyes seek out Beckett's, searching for something. And God, all Beckett can think about is how they're the same indigo as Castle's.

"No, he's meeting with his agent and Gram is at her acting school."

"Oh, um… okay. Do you have any idea what time he'll be back?"

Alexis flicked her eyes up at the ceiling, stopping herself before it could be a full eye roll, but Beckett got the idea. "Listen, Detective… Kate. You and I made our piece after Gram and Dad were held hostage at the bank but... you hurt him. And I can't just let you keep on doing that." She huffs out a breath before adding, "So if you have something to say to him, I'll relay the message." Alexis locks eyes with Beckett again, daring her to say something.

"No, you don't need to pass on any message. I just… can I talk to you?"

Alexis' eyebrows quirk up, confused, just like Castle's. "Me?" Beckett bites into her lip and nods. "Um, okay." Alexis pulls the door open and Beckett steps inside, relieved to find that the loft hasn't changed much since the last time she was here, during Martha's autobiographical play.

When Beckett turns around, having gotten lost in reverie, she finds Alexis at the kitchen countertop, busily fixing two cups of coffee. Beckett freezes, unsure of how to proceed, but sits across from Alexis when the young woman pushes one of the white cups towards her.

They both sip at their coffee, Alexis eyeing Beckett from behind the rim of her cup, before finally asking, "So, what did you want to talk to me about?"

Beckett sighs and carefully puts her cup down, running her fingers along the edge of the countertop before continuing. "Alexis, I care about your dad… a lot." _I love him, too. _"And it's taken me some time, but I… I want to be with him."

Alexis huffs out an irritated laugh. "Why did you wait this long? He's so hurt, Kate."

Beckett nods. "I know, and I'm so sorry for that. But I needed time to heal."

"From your shooting?"

Beckett considers running at the question, but she needs to face the facts. "That, but I think the wound is a lot older, too. I needed to come to terms with the potential loss that comes with loving someone. That's been hard for me since my mom died. But I love your dad… and I owe him that much."

For the first time since she opened the door, Alexis doesn't look angry at the detective, but rather, understanding. Sure she's still skeptical, but there's definitely empathy in those wild blue eyes. She's nodding, about to say something even, when the front door opens, revealing an unsuspecting Castle.

Castle notices Beckett just as he's shutting the door, and slams it a bit too hard. Alexis quickly gulps down her coffee and makes her way to the door. "Dad, Kate's here. I think you guys should talk." Alexis kisses him on the cheek, offering a small smile to Beckett, before grabbing her boat and exiting the loft.

Castle doesn't say anything as he pours himself a cup of coffee – black – and stands across from Beckett, choosing not to take his daughter's seat. "Beckett, what do you want?"

Beckett's momentarily taken aback by his harsh tone, but then nods, aware that it's justified, and stands up herself. She pushes back all of the linger doubt and reaches for Castle's face, all in.

Just as she's about to smear her lips over his, she murmurs, "You. I just want you."


	3. Chapter 3

**Note the change in rating.**

* * *

Kissing Kate Beckett is just as good as Castle expected, better even, except for the nagging feeling that something is off. Her lips are pressed against his, sending sparks of electricity all throughout his body, but there's a shortage somewhere. The hot press of her mouth can only do so much to deter Castel's thoughts, so — with the final vestiges of his willpower — he brackets both of her arms and pulls her off of him, pushing away gently.

Beckett's hazel eyes water a bit, but she quickly blinks away any evidence of her pain, and simply whispers, "No?"

Castle sighs and nearly loses it right there, wanting nothing more than to scoop her up into his arms and carry her straight to the bedroom. Well, almost nothing more. He wants the truth.

There's some sort of communication passed between them — always some kind, body language maybe — and Beckett understands what he needs. "Castle, I care about you. More than you may ever know. And I don't want anyone else." She rubs at her eyes, suddenly grateful for her lack of makeup, before continuing. "I don't want a British inspector or anymore meaningless relationships for that matter."

"What do you want, Kate?"

She huffs, and for the second time that day, says, "You. I just want you."

* * *

Although she's already said it, the truth behind her words finally hits him.

Castle tentatively steps forward, still weary of these walls that are threatening to crumble under the weight of his love, until the partners are close enough to share a breath.

Beckett presses her forehead against Castle's, and takes pleasure in the way his Adam's apple bobs. "Say something, Castle."

She feels more than sees the wrinkles form in his forehead, always so caught up in contemplation, but waits him out regardless. "Is it too soon? Are you ready? Because I'll wait; I'll always wait if I know that you're at the end."

Beckett presses her lips against Castle's in a chaste kiss, needing to show at least a little bit of her gratitude, before she pulls away, nodding. "I can't promise that this will be easy. But I want this. I want us." She seeks out one of his hands and gives it a squeeze. "And in the meantime," she whispers as a smirk forms on her lips. "...Although it might be difficult to tell you exactly what I'm feeling, let me start by showing you."

Castle pulls back in disbelief, trying to figure out how he's managed to misinterpret Beckett's words, but then she's pulling him towards his study. And then _oh _— into his bedroom, before she's pushing him to sit on the edge of the bed.

"Beckett—"

"Shh," she murmurs, removing her shirt with practiced ease. She's learned to do it with her right arm alone, despite the fact that she now has full mobility of both. Castle's in awe, hastily begin to work on his own shirt, but Beckett quickly bats his hands away. "Mine." Castle grins and pops the button on her jeans before pulling down the zipper. The cool metal briefly brushes her just where she needs it most but is gone all too soon.

Beckett kicks off her pants before crawling into Castle's lap and sucking on his pulse point, laving her tongue over the tendons of his neck as she works the buttons on his shirt — and soon his pants — undone.

In no time she's hovering over him, clad in only her bra and underwear and him in his boxers.

Beckett's palming Castle's through his boxers when he flips them, leaving them both in a brief daze, but smiling regardless.

It's not until he's unclasped her bra and is tugging down her panties that Beckett realizes what her partner is about to do. "Cas—"

"I want to taste you," he murmurs before kissing the puckered flesh between her breasts. "I want to know all of you."

All thought escapes Beckett when Castle covers one of her nipples with his hot mouth, pinching and rolling the other one, before releasing her with a wet pop and paying homage to her other soft mound.

She's moaning as he kisses his way down her chest, then stomach, then the creases of her thighs. "Castle, _please_."

He doesn't tease her for much longer, too eager himself to get a taste of the future, and presses his mouth to the sensitive bundle of nerves at her front.

She nearly rockets off of the bed and he has to lay a hand on her abdomen, smiling at the feel of her twitching muscles, before sliding his tongue through her slick, wet folds.

The fingers of the hand that aren't holding Beckett down brush through her folds — one, then two of his thick digits entering her core as he continues to suck on her clit.

She's moaning and writhing, all the while chanting "Castle, Castle, Castle", undone all too quickly yet not soon enough.

It's with a few more twists of his fingers and one final graze of his teeth over her clit that the white-hot bursts of ecstasy hit, sending spasms throughout her body before rendering Beckett truly limp and sated.

Castle slumps next to her, watching her come apart quite possibly the hottest thing he has ever seen, and basking in the after-glow of her being.

Neither are quite sure how long they lay there, legs tangled together, but soon enough Beckett is climbing on top of him and pulling off his boxers, a wicked grin gracing her lips as she strokes his hot, thick length. "I'm sorry we couldn't get to this sooner."

Castle groans, but still manages to roll his partner beneath him, watching as she is once again — pleasantly — surprised. "It's okay. We have all day… night."

Beckett bites her bottom lip before adding, "I think you and I have a lot longer than that."

Castle pauses — both aware of the weight of her words — but knows that they'll talk about it later. He locks eyes with her as he teases her entrance with his tip, searching for any last shred of doubt, but finds nothing other than certainty, to which he slides home.


End file.
